/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/MeshConstraints.h
EEdgeRefineFlags indicate constraints on triangle mesh edges
namespace UE { namespace Geometry { enum EEdgeRefineFlags { NoConstraint = 0, NoFlip = 1, NoSplit = 2, NoCollapse = 4, FullyConstrained = NoFlip | NoSplit | NoCollapse, SplitsOnly = NoFlip | NoCollapse, FlipOnly = NoSplit | NoCollapse, CollapseOnly = NoFlip | NoSplit, } } }